This table shows how the amount of money Sadie makes from selling lemonade is related to the number of cups sold. How much does one cup of lemonade cost?

Answer:
One cup of lemonade will cost $2.
Step-by-step explanation:
From simple observation and visual inspection we can conclude that one cup of lemonade costs $2.
If 9 cups of lemonade cost $18 then one cup of lemonade will cost $18÷9 = $2
If 2 cups of lemonade cost $4 then one cup of lemonade will cost $4÷2 = $2.
Therefore we can conclude that one cup of lemonade will cost $2.